Dimethylformamide → ethyl 4,6-dichloro-3-formyl-1H-indole-2-carboxylate

HRID 582051Notes

Reaction equation

HRID 582051 reaction equation
[C:1]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[C:12]([Cl:15])[CH:11]=[C:10]([Cl:16])[CH:9]=2)([O:3][CH2:4][CH3:5])=[O:2].CN(C)[CH:19]=[O:20].P(Cl)(Cl)(Cl)=O>ClC(Cl)C>[CH:19]([C:14]1[C:13]2[C:8](=[CH:9][C:10]([Cl:16])=[CH:11][C:12]=2[Cl:15])[NH:7][C:6]=1[C:1]([O:3][CH2:4][CH3:5])=[O:2])=[O:20]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 2736407ethyl 4,6-dichloro-1H-indole-2-carboxylate

Product 1

HCID 2794948ethyl 4,6-dichloro-3-formyl-1H-indole-2-carboxylate

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent

Conditions

Temperature
80 °C

Procedure

Combine 2-carboethoxy-4,6-dichloroindole (10.0 g, 0.039 mol), and dimethylformamide (4.5 mL, 0.057 mol) in dichloroethane (20 mL). Add phosphoryl chloride (8.9 g, 0.058 mmol). Heat to 80° C. After 18 hours, cool the reaction mixture to ambient temperature to give a solid. Filter the solid and combine with aqueous 1 M sodium acetate solution and stir. After 18 hours, filter, rinse with water, and dry to give the title compound: mp 216-217° C.; Rf =0.24 (silica gel, 1/1 ether/hexane); 1H NMR (CDCl3) δ 10.80 (s, 1 H), 9.40 (br s, 1 H), 7.39 (s, 1 H), 7.35 (s, 1 H), 4.52 (q, 2 H, J=7.2 Hz), 1.47 (t, 3 H, J=7.1 Hz).

Workup

  1. temperaturecool the reaction mixture to ambient temperature
  2. customto give a solid
  3. filtrationFilter the solid
  4. waitAfter 18 hours
  5. filtrationfilter
  6. washrinse with water
  7. customdry

Sources & evidence

ORD record
ord-0311d52ce71e417993243c49c32aa97b
Source dataset
uspto-grants-1999_07
Patent number
US05922752

Reaction notes

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